Magnetic door catch



United States Patent MAGNETIC DOOR CATCH Macy 0. Teeter, New Orleans, La.

Application April 12, 1952, Serial No. 282,050

13 Claims. (Cl. 292-2515) This invention relates to a device for retaining a door or other closure member in closed position by magnetic attraction.

It is common experience with cabinetware that considerable difilculty is often encountered with the operation of the cabinet latch or'catch because of warpage, sagging, or other misalignment of portions of the cabinet either during or after the initial installation. In the usual type of cabinet catch, one of the catch elements is fastened to the door and the companion catch element is mounted in coacting position on the cabinet frame or shelf. Consequently even a slight degree of change in the relative positions of the cabinet frame and door will result in improper contact between the catch elements which can usually be corrected only by removing one or both catch elements and remounting them in properly aligned positions.

In my prior U. S. Patent No. 2,508,305 issued May 16, 1950, I have described and claimed a magnetic door catch which overcomes the above-mentioned objections ordinarily encountered in cabinet catches. The magnetic catch comprises a pair of cooperating magnet and armature elements adapted to be mounted in self-adjusting coacting positions on a door and its adjacent frame structure. One of the catch elements is rigidly mounted on its supporting member and the other catch element is resiliently and loosely mounted for outward movement toward the rigidly supported catch element when the door is in closed position. Simultaneously with such outward movement, the movable catch element may also undergo limited angular or rocking movement to permit automatic full surface engagement between the contact faces of the catch, elements even though there may be relative misalignment between the door and frame structure.

The present invention relates to a novel magnetic catch having a substantially simplified and more economical construction as compared with the device shown in my prior patent but which also possesses the same general advantages and operating characteristics as the previously patented device. As will hereinafter appear, the magnetic catch comprising the present invention utilizes a molded rubber mounting for the magnet element and thus I am able to: reduce the quantity of metal required as well as to eliminate the use of metal. springs. In addition, as explained. below in detail, the present construction greatly simplifies and reduces the cost of the magnet element of the device.

Accordingly, a primary object of the present invention is to provide a novel magnetic catch characterized by simplicity of construction and operation and which is relatively inexpensive to manufacture.

A further object of the invention is to provide a novel magnetic catch consisting of relatively few parts whereby the catch may be easily assembled and installed.

Another object of the invention is .to provide a novel simplified form of magnetic catch which relies .on a re- 2,733,092 Patented Jan. 31, 1956 silient rubber mounting rather than the use of metal springs to provide resilient catch action.

An additional object of the invention is to provide a novel magnetic catch in which a comparatively less expensive form of magnet element can readily be used.

Still another object of the invention is to provide a novel magnetic door catch for cabinetware or the like which is simple in construction and operation and which functions effectively even though the portions of the cabinet structure which support the catch elements become misaligned relative to each other through warpage, sagging, or other causes.

Other objects and advantages of the invention will become apparent from the subsequent detailed description of the invention taken in connection with the accompanying drawings, wherein:

Fig. 1 is a front elevational View, on a reduced scale, of a cabinet provided with a magnetic door catch comprising one embodiment of the invention and showing the location of the magnet unit of the device;

Fig. 2 is a vertical sectional view taken along the line 22 of Fig. 1 and showing the position of the magnet unit when the cabinet door is open;

Fig. 3 is a view similar to Fig. 2 but with the cabinet door in closed position;

Fig. 4 is a horizontal sectional view showing the manner in which one of the catch elements adjusts itself antomatically to permit effective full face contact with the other catch element in spite of relative misalignment of the cabinet door and frame structures;

Fig. 5 is a vertical sectional View taken along the line 55 of Fig. 2; and i Fig. 6 is an exploded perspective view showing the various parts of the device in disassembled relation.

Referring now to the drawing, a woodencabinet is shown in Fig. 1 comprising a cabinet frame 11 and a shelf 12. The cabinet is provided with a magnetic door catch embodying the features of my invention and consisting of a magnet unit 13 mounted at the underside of the shelf 12 and a cooperating armature unit 14 secured in a corresponding location at the inner face of a door 16 (not shown in Fig. l) which is hingedly secured to the frame 11. It will be understood that the magnet unit 13 and the armature unit 14 are thus mounted in coacting positions on the cabinet and door, respec tively, so that the armature engages the magnet when the door 16 is in closed position adjacent the cabinet frame.

Although as shown in the drawing the magnet unit 13 .is secured to the cabinet and the armature unit 14 is secured to the door, it will be understood that the unit 13 may be modified to constitute the armature unit and the unit 14 changed to a magnet unit if desired. Also, the magnet and armature units need not necessarily be mounted in the exact positions on the cabinet structure illustrated in the drawing. For example, the catch'elements may be positioned adjacent the bottom or top portions of the cabinet frame if desired. r

In Figs. 2 to .6, the magnet unit 13 is shown as comprising an elongated bar magnet 1-7 having molded therearound a block or support designated generally at 18 and formed from rubber or other natural or synthetic elastomer having flexible, resilient, and elastic properties. The rubber support 18 is formed to provide a forward magnetmounting portion 19, a rearwardly extending apertured boss or lug 21 for attaching the unit, and an intermediate cut-away or restricted portion which in this case is in the form of a slot 22. The bar magnet 17 is firmly embedded in the forward portion 19 of the rubber support and projects slightly from the front face of the support in order to facilitate complete full face contact with the armature unit.

The attaching boss 21 has an elongated aperture 23, and the unit is secured to the shelf 12 by means of a screw 24 and a generally U-shaped protective metal clip 26 adapted to fit over the boss 21 in the manner best seen in Fig. 5. The cap 26 has an elongated opening 27 adapted to be aligned with the aperture 23 in the boss 21, and the screw 24, having an enlarged head 28, extends through the aligned openings into the supporting structure such as the shelf 12. Thus, the entire magnet unit is mounted by means of only a single screw, and the elongated openings 23 and 27 permit the unit to be adjusted to desired location before final tightening of the screw 24. A plurality of barbs or tangs 29 are formed at the ends of the legs or sides of the clip 26 and it will be understood that these are embedded in the shelf 12 or other supporting structure when the screw 24 is fully tightened thereby preventing the unit from twisting or slipping out of position. The metal clip 26 thus clamps the rubber boss 21 securely against the shelf 12 and at the same time prevents the rubber from being squashed or distorted by the pressure of the screw head 28.

Although any suitable magnetic metal or alloy may be employed for the bar magnet 17, the alloy of aluminum, nickel, and cobalt known commercially as Alnico is particularly desirable. For maximum economy and convenience the magnetic metal may be cast as an elongated bar or strip divided into sections by means of notches. The elongated casting may then be readily broken at the notches to provide a plurality of magnet elements 17, and the fragments of the broken notched portions constitute end shoulders or extensions for each individual magnet element, as indicated at 31 in Fig. 4, which assist in retaining the magnet securely within the molded rubber support 18. Inasmuch as each bar magnet 17 so formed is encased in a molded rubber block 19, it is unnecessary to perform expensive machining or finishing operations on the bar magnet elements except for the front contact faces thereof. The construction of the magnet unit 13 thus lends itself readily to substantial savings, particularly in the manufacture of the magnet element which is often the most expensive part of a magnetic catch.

The armature unit 14 comprises an elongated strip or plate 32 of magnetically attractable metal, such as iron or steel, which is substantially coextensive with the bar magnet 17. This plate is attached to the door 16 by means of a screw 33 extending through a central aperture 34 and with the head of the screw countersunk in the plate to provide a flat contact surface for engaging the magnet 17. A pair of points or indentations 36 are provided adjacent the ends of the plate 32 for embedding themselves in the wood and preventing turning or twisting of the armature element out of position.

Referring particularly to Figs. 2 to 4, the operation of the device will now be described. The inherent elastic or resilient nature of the rubber support 18 together with the provision of the slot 22 therein permits expansion and retraction of the rubber support for moving the magnet element 17 away from and toward the armature on the door 16. In Fig. 2, the rubber support 18 is shown in its normal retracted position when the door 16 is open and the armature unit is therefore beyond the area of influence of the magnet element 17. It will be seen that in this position the slot 22 is restricted in width. In Fig. 3 I have illustrated the relative positions of the catch elements when the door 16 is in closed position. As shown in the drawing, the door 16 when closed is spaced slightly from the front edge of the shelf 12 and, in addition, the magnet unit 13 is mounted in predetermined location so that the magnet element 17 is recessed slightly from the front edge of the shelf 12 when the rubber support 18 is in its normally retracted position (Fig. 2) corresponding to the open position of the door 16. As a result of this relation, it will be seen that the magnet element 17 must move outwardly toward the armature element 32 in order to contact the latter. This outward movement is clearly illustrated in Figs. 3 and 4, and it will be seen that the slot 22 is expanded during such outward movement of the magnet element 17 and the mounting portion 19 of the rubber support 18. In this position the magnet 17 adheres to or establishes firm contact with the armature plate 32 on the door but the actual retention of the door in closed position is accomplished through the resilient action of the expanded rubber support 18.

it will be evident that the magnetic attractive forces between the magnet element 17 and the armature element 32 are greater than the force exerted by the expanded rubber support 18 tending to retract the magnet element, thereby permitting the above-described outward movement of the magnet when the door is in closed position. However, when the door 16 is in open position the magnet 17 automatically returns to its Fig. 2 position. In Figs. 2, 3 and 4, the general forward and rearward movement of the magnet element corresponding to closing and opening of the door 16 is illustrated by means of a doubleheaded arrow on the magnet 17.

In order to realize proper functionin of the magnetic catch above described and to completely avoid undesirable looseness or rattling of the closed door, it is important that a certain minimum spacing be provided between the armature element and the normal retracted position of the magnet element so that when the door is closed the magnet element must necessarily move outwardly in order to contact the armature element and thereby place the rubber support 18 under elastic or resilient tension due to expansion thereof. In the embodiment shown in the drawing, this spacing is accomplished by predetermined recessed mounting of the magnet unit 13 and by a spaced relation between the door 16 and the shelf 12 when the door is closed. This latter spacing can be effected by having the shelf 12 recessed slightly from the peripheral cabinet frame or jamb against which the door 16 abuts, or suitable bumpers can be utilized. However, it will be understood that various other arrangements such as recessing of one or both catch elements may also be utilized to obtain the same spacing effect.

Extending upwardly from the magnet mounting portion 19 of the rubber support 18 and at the forward edge of the slot 22 I have provided a small projection or spacer 37 the purpose of which is to hold the movable forward portion 19 of the rubber support 18 away from full contact with the adjacent surface of the shelf 12. In this way, I avoid any possibility that improper mounting of the unit or excessive tightening of the screw 24 may bind the forward portion 19 against the shelf surface so as to interfere with proper flexibility and free movement thereof. Of course, it will be seen that the height of the attaching boss 21 is greater than the corresponding dimension of the forward portion 19 of the support 18 so as to space the latter from the adjacent shelf surface. However, the provision of the spacer 37 forwardly of the boss 21 further insures the desiredfreedom of back and forth movement of the forward portion of the magnet support. A similar projection or spacer 38 (Figs. 2 and 3) is provided at the other side of the rubber support in the event that the unit is mounted with this side against the supporting surface.

As hereinbefore mentioned, an important feature of the present invention resides in the self-adjustability of the catch elements to permit effective full face contact between the magnet and its armature even though the cabinet door and its adjacent frame structure may occupy misaligned non-parallel positions as a result of war-page, sagging or other causes. This aspect of the invention is illustrated in Fig. 4 wherein the ideal situation of perfect alignment between the door and frame structure is illustrated in solid lines and the misaligned condition is shown in broken lines. In the broken line modification, the door 16 is disposed in an angular plane and, as a result, the entire forward portion of the rubber support 18 undergoes angular or twisting movement to permit full face fiatwise engagement between the forward contact face of the magnet element 17 and the corresponding contact face of the armature element 32. Such angular or cocking movement of the magnet support is of course permitted by reason of the inherent flexible and distortable nature of the rubber comprising the support 18 and also because of the slot 22 which leaves in the support an easily distortable region of restricted size.

In Fig. 4 the misalignment of the door relative to the cabinet frame is illustrated in a horizontal plane but it will be quite apparent that the structure of the catch is such that even if the cabinet door and frame aremisaligned in a vertical plane, a limited degree of angular or cocking movement of the forward portion of the support 18 can also occur in a vertical plane. Hence, the magnetic forces in my device are utilized to their fullest extent at all times with the self-adjustability of the movably mounted catch element compensating for all types of misalignment between the door and frame.

Although, for the sake of illustration, I have shown the rubber support 18 as being provided with an elongated slot 22, it will be understood that this portion of the structure can be modified as desired. The important objective is to provide an area or region of restricted dimensions for connecting the forward or magnet-mounting portion of the support to the rearward or attaching portion of the support thereby permitting a limited degree of back and forth and also angular or cooking movement of the magnet-mounting portion relative to the attaching portion.

From the foregoing description, it will be seen that the present invention provides a novel and simplified form of magnetic catch which is relatively inexpensive to manufacture and which may be easily installed by the user. The catch has a minimum number of parts and does not involve the use of metal springs to provide resilient action. In addition, because of the substantial enclosure of the magnet element in a molded rubber support, I am able to utilize a relatively less expensive form of cast magnet and I am also able to eliminate a substantial portion of the machining and finishing operations which are normally necessary in a magnetic device of this character.

Alhough the invention has been described in detail in connection with a certain specific embodiment, it will be understood that various modifications and equivalent structnres may be resorted to without departing from the scope of the invention as defined in the appended claims.

I claim:

1. In a magnetic catch including pair of cooperating magnet and armature elements adapted to be mounted in coacting positions 'on a door and frame structure, a resilient support for mounting one of said elements in position on said structure, said support comprising a onepiece molded flexible resilient member of rubber or the like having a movable forward portion with said one element embedded therein and a rearward attaching portion adapted to be secured in fixed relation on said structure, said one element having an exposed face for contacting said other element and said member being provided with an elongated slot intermediate said one element and said attaching portion whereby to permit back and forth resilient movement of said forward portion and said one element for engaging and disengaging said other element and also permitting limited angular or cocking movement of said forward portion and said one element for aligning the latter with the other element in the event of misalignment of said door and frame structure.

2. In a magnetic catch, a magnet unit comprising an elongated bar magnet, a one-piece rubber support having a generally rectangular portion molded around said magnet with one longitudinal face of the magnet projecting slightly from the support at one side of the latter for contacting an armature element, and an integral boss extending transversely from said rectangular portion at the opposite side of said support and having an aperture therethrough for receiving a fastening element for securing the support to a surface, said support having an elongated slot intermediate said magnet and said boss whereby said rectangular portion carrying the magnet is resiliently movable outwardly and angularly relative to said boss for permitting contact of the magnet with an armature element and for automatically aligning the same.

3. In a magnetic catch, a magnet unit comprising an elongated bar magnet, a one-piece magnet support comprising a generally rectangular block of molded rubber or the like having said magnet embedded therein with one longitudinal face of the magnet projecting slightly from one side of the block for contacting an armature element, and an integral attaching portion extending outwardly from the opposite side of the block and adapted to be secured to a surface, said block being formed with an elongated slot adjacent said opposite side thereof whereby to permit outward resilient movement of the magnet-containing portion of the block for effecting contact of the magnet with an armature element and whereby to permit limited angular or cocking movement of the magnet-containing portion of the block longitudinally of the magnet V for automatically aligning the magnet with the armature element.

4. In a magnetic catch, a magnet unit comprising a supporting member of molded rubberlike material adapted to be secured adjacent one side thereof to a surface, and a permanent magnet element embedded at the opposite side of said member and having one face thereof exposed for contacting an armature element, said supporting member being provided with a slot intermediate the magnet element and said one side thereof whereby to facilitate fiexible resilient outward and angular movement of the magnet and the surrounding portion of said member for permitting contact of the magnet with an armature element.

5. In a magnetic catch, the combination of a magnet unit comprising a one-piece support of molded rubber or the like having a permanent magnet element embedded at one side thereof and having an outwardly extending boss at the oppositc side thereof, and a generally U-shaped protective clip adapted to fit over said boss and to be secured to a surface for clamping the support to'the surface without excessive distortion of the boss.

6. In a magnetic catch, the combination of a magnet unit comprising a one-piece support of molded rubber or the like having a permanent magnet element embedded at one side thereof and having an outwardly extending boss at the opposite side thereof, said boss having an elongated aperture therethrough, and a generally U-shaped protective clip adapted to fit over said boss and having an elongated aperture registrable with the aperture in said'boss whereby to permit a fastening element to extend through the aligned apertures for clamping the support to a surface without excessive distortion of the boss by the fastening element, the elongated character of said apertures permitting the support to be adjusted relative to the fastening element.

7. In a magnetic catch, a magnet unit comprising a resilient one-piece body member of molded rubber or the like having a rear portion adapted to be secured against a supporting surface and a forward portion having a permanent magnet retained therein, said forward portion being resiliently movable away from and toward said rear portion in a plane generally parallel to the supporting surface for permitting engagement of the magnet with an armature element, and means on said body member extending transversely to said plane of movement for holding said forward portion in spaced relation from the supporting surface whereby to facilitate free non- 7 binding movement thereof.

8. In a magnetic catch, a magnet unit comprising a resilient one-piece body member of molded rubber or the like having a magnet-mounting portion with a permanent magnet element retained therein and an outwardly extending boss adapted to be secured in fixed relation against a supporting surface, said magnet-mounting portion being resiliently and flexibly movable away from and toward said boss in a plane generally parallel to the supporting surface for permitting contact of the magnet element with an armature element, and said boss extending transversely to said plane of movement and beyond. said magnet-mounting portion at opposite sides thereof whereby the magnet-mounting portion is held in generally parallel spaced relation from the supporting surface and free non-binding movement of said portion is thereby facilitated.

9. In a magnetic catch, a magnet unit comprising a resilient one-piece body member of molded rubber or the like having a magnet-mounting portion with a permanent magnet element retained therein and an outwardly extending boss adapted to be secured in fixed relation against a supporting surface, said magnet-mounting portion being resiliently and flexibly movable away from and toward said boss in a plane generally parallel tothe supporting surface for permitting contact of the magnet ele ment with an armature element, and a spacer extending transversely to said plane of movement and to said magnetmounting portion of the body member for holding the latter in generally parallel spaced relation from the sup porting surface whereby to permit free non-binding movement of said portion.

10. In combination, a supporting surface, a magnet unit mounted on said surface and comprising a one-piece resilient body member of molded rubber or the like having a magnet-mounting portion with a permanent magnet secured therein, an integral attaching boss extending from said portion, fastening means holding said boss in sccured relation against said surface, said magnet-mounting portion being resiliently movable away from and toward said boss in a plane generally parallel to said sun face for permitting contact of the magnet with an armature element and said boss extending transversely to said plane of movement and beyond said magnet-mounting portion at opposite sides thereof whereby the magnetmounting portion is held in generally parallel spaced relation from said surface, and a spacer extending trans versely to said plane of movement and to said magnetmounting portion and in engagement with said surface for retaining said portion in said spaced relation whereby to facilitate free non-binding movement of said portion.

11. In a magnetic catch, a magnet unit comprising a resilient one-piece body member of molded rubber or the like having a magnet-mounting portion with a per manent magnet element retained therein and an outwardly extending boss adapted to be secured in fixed relation against a supporting surface, said magnet-mounting portion being resiliently and flexibly movable away from and toward said boss in a plane generally parallel to the supporting surface for permitting contact of the magnet element with an armature element and said boss extending transversely to said plane of movement and beyond said magnet-mounting portion at opposite sides thereof whereby the magnet-mounting portion is held in generally parallel spaced relation from the supporting surface, and a spacer extending transversely to said plane of movement andto said magnet-mounting portion of the body member for holding the latter in generally parallel spaced relation from the supporting surface whereby to facilitate free non-binding movement of said portion.

12. In combination, a supporting surface, a magnet unit mounted on said surface and comprising a one-piece resilient body member of molded rubber or the like having a magnet-mounting portion with a permanent magnet secured therein, an integral attaching boss extending from said portion, and fastening means holding said boss in secured relation against said surface, said magnet-mounting portion being resiliently movable away from and toward said boss in a plane generally parallel to said surface for permitting contact of the magnet with an armature element and said boss extending transversely to said plane of movement and beyond said magnetmounting portion at opposite sides thereof whereby the magnet-mounting portion is held in generally parallel spaced relation from said surface and free non-binding movement of said portion is thereby facilitated.

13. In combination, a supporting surface, a magnet unit mounted on said surface and comprising a one-piece resilient body member of molded rubber or the like hav ing a magnet-mounting portion with a permanent magnet secured therein, an integral attaching boss extending from said portion, and fastening means holding said boss in secured relation against said surface, said magnetmounting portion being resiliently movable away from and toward said boss in a plane generally parallel to said surface for permitting contact of the magnet with an armature element and said magnet-mounting portion of the body member having an integral spaced element extending transversely to said plane of movement and in engagement with said surface for retaining said portion in generally spaced relation from said surface whereby to facilitate free non-binding movement of said portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,471,635 Mark et al. May 31, 1949 2,508,305 Teetor May 16, 1950 2,519,435 Byrd Aug. 22, 1950 2,609,221 Schultz Sept. 2, 1952 2,659,118 Anderson et al. Nov. 17, 1953 

